Another line of work in audio is that of neural vocoders based on a denoising diffusion process. WaveGrad [1]} and DiffWave [2]} are conditioned on the mel-spectrogram and produce high-fidelity audio samples, using as few as six steps of the diffusion process. These models outperform adversarial non-autoregressive baselines. [3]} propose a text-to-speech diffusion base model, which allows generating speech with the flexibility of controlling the trade-off between sound quality and inference speed.
